Record details

Title
    Alkaline and Carbonate-rich Melt Metasomatism and Melting of Subcontinental Lithospheric Mantle: Evidence from Mantle Xenoliths, NE Bavaria, Bohemian Massif
Author
    Ackerman, Lukáš
    Balogh, K.
    Hegner, E.
    Magna, T.
    Svojtka, Martin
    Špaček, Petr
    Ulrych, Jaromír
Language
    anglicky
Publication type
    článek v odborném periodiku
Source title - serial
    Journal of Petrology
Vol./nr.
    Roč. 54, č. 12
Pages
    s. 2597-2633
Year
    2013
Notes
    Projekt: GA205/09/1170, GA ČR3cav_un_auth*0252833
    Rozsah: 37 s. : E
    Výzkumný záměr: CEZ:AV0Z30120515
    Výzkumný záměr: CEZ:AV0Z30130516
Subject category
    metasomatism
    microstructure
    peridotite
    Sr-Nd-Li isotopes
    subcontinental lithosphere
Keyword
    Alkaline
    Bavaria
    Bohemian
    Carbonate-rich
    Evidence
    Lithospheric
    Mantle
    Massif
    Melt
    Melting
    Metasomatism
    NE
    Subcontinental
    Xenoliths
Abstract (in english)
   Peridotite xenoliths hosted by Cenozoic basanite lava flows (21?2^23?5 Ma) occur at several localities in the western continuation of the Ohr>e/Eger rift (Central European Volcanic Province) in NE Bavaria, Bohemian Massif. Detailed petrography, major and trace element compositions of whole-rock samples and selected mineral phases as well as Sr^Nd^Li isotopic compositions for a suite of mantle xenoliths from Zinst, Hirschentanz andTeichelberg document variable degrees of partial melting and metasomatism. Melting models based on whole-rock major element composition and Cr# of spinel indicate 6^30% melting in the spinel stability field.
   Subsequent metasomatism by alkaline and carbonate-rich melts resulted in modal and cryptic metasomatism, expressed by the presence of carbonate-bearing silicate melt pockets with complex secondary mineral assemblages and by enrichment in light rare earth elements, Li, Rb, U, Pb, high field strength elements and P.The carbonate is most probably associated with fractionation of the Na-rich silicate melt. High P contents, variable but low to negative d7Li values from þ2?5 to 9?7ø, coupled with 87Sr/86Sr ratios between 0?7032 and 0?7041 may reflect a significant contribution of recycled crustal material such as eclogite in the infiltrating melts responsible for metasomatism, although the Li isotope compositions may reflect kinetic modifications through diffusion.
    The trace element geochemistry of clinopyroxene, carbonate and melt pockets suggests that clinopyroxene plays a very important role in fractionation of the rare earth elements, high field strength elements and Sr, whereas carbonate does not host large quantities of incompatible trace elements except for Sr, Ba and, to a lesser extent, Th and U.
Contributor
    AV ČR Brno, Geologický ústav
Contributor code
    AV ČR, GLÚ
Source format
    U
Import date
    23. 10. 2014